<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>CSS层次选择器</title>
		<link href="css/CSS层次选择器.css" rel="stylesheet" type="text/css">
	</head>
	<body>
		<div id="box1">
			盒子1
			
			<div id="box3">
				盒子3
			</div>
			
			<div id="box4">
				盒子4
				
				<div id="box5">
					盒子5
			    </div>
			
			</div>
		
		</div>
		<div id="box2">
			盒子2
			<div id="box22">
				盒子22
			</div>
		</div>
		<div id="box6">
			盒子6
			<div id="box22">
				盒子66
			</div>
		</div>
	
	</body>
</html>
